Abnormal Newborn Screening Follow-Up Testing

Newborn screening is a public health activity aimed at the early identification of genetic conditions. The screening programs are headed by each state department of health and available to all infants in the United States. To test for these diseases, shortly after birth, a baby's heel is pricked and a small sample of blood is collected. While most infants look perfectly healthy, there are some disorders that aren't visible. Unless these conditions are treated early, they can cause some damage to the baby. If the NBS test is abnormal, follow-up testing must be done to confirm a diagnosis. Timely intervention for these disorders can lead to the elimination or reduction of morbidity, mortality, and disabilities.

Most infants with abnormal newborn screening results have normal follow-up testing. Initial NBS results can be abnormal because the blood was drawn too early, the baby is premature and many other reasons. If a baby truly has a disorder, treatment can be started immediately.

In 2005, the American College of Medical Genetics (ACMG) recommended 29 diseases to be included in all newborn screening programs. Screening tests do not primarily determine disease status but measure substances in the blood that are associated with disease but may not be diagnostic. Abnormal results require follow-up diagnostic testing to determine disease status.